Chapter 7 - Bone Structure and Function Flashcards Preview

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Flashcards in Chapter 7 - Bone Structure and Function Deck (53):
1

What are the 4 functions of the skeletal system?

1) provide support and protection
2) assist body in movements
3) participate in blood cell production
4) storage of mineral and energy reserves

2

what are the 3 main components of a long bone?

1) Diaphysis - shaft
2) Epiphyses - forms the distal and proximal ends of a long bone
3) Metaphyses - area btw diaphysis and epiphyses

3

How do bones store minerals and energy?

fats are stores in adipose tissue of yellow bone marrow.
calcium and phosphorus are also stored in the bone.

4

explain how bones assist in movements

muscles pull on bones to form movements

5

in what ways do bones provide structure and protection for the body.

-structural framework
-point of attachment for tendons and ligaments
-protects internal organs

6

what are the characteristics of Compact Bone

-strongest form of bone tissue
-resists stresses from weight and movement
-located on the outside of bone

7

What are the characteristics of spongy bone?

-located within compact bone
-supports and protects red bone marrow

8

What is Articular Cartilage and where is it found?

thin layer of hyaline cartilage that covers the epiphysis of long bones. It is on articular surfaces of bone.

9

What type of cartilage makes up the intervertebral discs and is found in the pelvis and knees?

Fibrocartilage

10

A tough sheath of dense irregular CT located on the outside of the bone is called _______________.

Periosteum

11

A space that contains fatty yellow bone marrow in adults is called the _____________________.

Medullary Cavity

12

What is the Endosteum?

a membrane that lines the medullary cavity

13

What are the general characteristics of Red Bone Marrow?

1) Hemopoietic (forms blood cells)
2) contains reticular CT (scaffolding), immature blood cells, and fat

14

how does Red Bone Marrow differ btw children and adults?

children: in spongy bone and medullary cavity of long bones. Children need more because they are still growing (higher metabolism)
Adults: located in portions of axial skeleton and proximal epiphyses of humorous and femur.

15

_______________ is a product of Red Bone Marrow degeneration.

Yellow Bone Marrow

16

what the general characteristics of Yellow Bone Marrow?

1) product of Red Bone Marrow degeneration.
2) stores fat
3) can convert back to red bone marrow during severe anemia
4) in adults it is found in medullary cavity of long bones

17

Osteoprogenitor cells

unspecialized bone stem cells.
mature into osteoblasts and then osteocytes

18

osteoblasts

bone building cells

19

osteoclasts

cells that break down bone
do not arise from osteoprogenitor cells

20

osteocytes

mature osteoblasts

21

what is the chemical composition of bone?

15% water
30% collagen fibers
55% mineral salts: Calcium phosphate, calcium carbonate, trace elements (magnesium, fluoride, sulfate)

22

Units of compact bones are called _____.

Osteons

23

Osteons are made up of _____________.

Concentric lamellae

24

what are interstitial lamellae?

leftover fragments of older osteons that lie between osteons.

25

small spaces btw lamellae that house osteocytes are known as __________.

Lacunae

26

Osteocytes are located inside which structure?

Lacunae

27

Describe Canaliculi.

small dendritic-like channels that connect lacunae

28

Blood, lymphatic tissue and nerves are located in this structure within a bone.

central canal

29

Spongy Bone contains osteons. True/ False.

False

30

what is trabecular?

lattice of thin columns of lamellae.

31

the process of forming new bone is called __________.

ossification

32

When does ossification occur?

1) initial formation (babies / children)
2) growth
3) remodelling
4) repair of fractures

33

breaking down and reforming new bone matrix is known as __________. what is important for this function?

remodelling
balance between osteoblast and osteoclast activity

34

Describe bone growth.

-adolescents have an epiphyseal growth plate at the epiphyses of long bones
-contains hyaline cartilage
-where new bone is added

35

in adults, the epiphyseal growth plate become the _________________.

epiphyseal line

36

growing cartilage is replaced with calcified bone at what stage in life?

adulthood

37

bone over growth is a result of ___________. this is called ____________.

more osteoblast activity than osteoclast activity.
acromegaly

38

osteoporosis refers to....

too much osteoclast activity relative to osteoblast activity

39

what factors are involved in bone metabolism

1) minerals - (calcium, phosphate, magnesium, manganese, fluoride)
2) viramins - (A, C, D, K, B12)
3)hormones - Human Growth Hormone, IGF, thyroid hormones, sex hormones

40

explain vitamin D synthesis

- UV light converts to precursor Vitamin D3 (cholecalciferol)
- In liver: Vitamin D3 is converted to Calcidiol (add OH-)
- In Kidney: Calcidiol is converted to calcitrol (Vitamin D) (by adding OH-)
- Vitamine D stimulates uptake of calcium from small intestine

41

How are calcium and phosphate levels balanced between blood and bone?

Parathyroid Hormone (Ca2+ is low) and calcitonin (from thyroid when Ca2+ is high)

42

What processes occur when blood calcium levels decrease?

1) parathyroid gland releases PTH
2) PTH and Calcitrol increase osteoclast activity
3) calcium is released into the blood
4) kidneys begin to excrete less calcium through urine
5) calitrol increases absorption of calcium from sm intestine into the blood
****Blood calcium levels increase

43

what processes occur when blood calcium levels are elevated

1) Thyroid gland releases calcitonin
2) calcitonin inhibits osteoclast activity
3) Kidneys are stimulated to increase the amount of calcium lost through urine

44

A Comminuted Fracture is ________________.

bone is splintered into several spall pieces between the main parts

45

When a bone is split into two or more pieces it is know as ____________.

complete fracture

46

what is a compound fracture?

broken ends of the bone protrude through the skin

47

a partial fracture in which one side of a bone breaks and the other is bent is known as ______.

greenstick fracture

48

a hairline fracture is _____.

fine crack in which sections of bone remains aligned (common in skull)

49

when one fragment of bone is firmly driven into another it is called....

impacted fracture

50

A stress fracture is......

this fractures due to repeated, stressful impact such as running.
difficult to see on x-rays
may need a bone scan to accurately identify them

51

What are the 4 processes of bone repair?

1) Fracture Hematoma forms (6-8 hours after)
2) fibrocartilaginous callus forms (soft callus) - dense CT and collagen (3 weeks)
3)Boney callus forms - CT and collagen is replaced with bone (3-4 months)
4) Remodelling - compact bone is formed, osteoclasts clean up

52

What makes bone tissue stronger? Why?

mechanical stress
-deposition of mineral salts
-increase osteoblast activity

53

How does age affect bone tissue?

- bone mass decreases due to decrease in sex hormones (important in maintaining bone growth)
- occurs in middle age (30)